Fiber image guides, both coherent fiber bundles or single gradient-index fibers, are used for transmitting image signals from one end of the guide to the other end of the guide. A typical fiber bundle contains thousands of individual fiber pixels disposed in an ordered and coherent manner at their end termination. Such a fiber image guide has been successfully used in various medical endoscopic and industrial inspection applications. High resolution analog images have been achieved for certain image guides having a length of several meters. Relatively low loss (e.g. 2 dB over a distance of 10 meters) transmission can be achieved at certain transmission wavelengths by the selection of the materials used to fabricate the fiber image guide.
Modern information oriented sciences and technology are mainly driven by rapid advances in computer technology. One visible trend in computer hardware technology is that the central processing units or CPUs will process data in larger and larger parallel formats, from 8-bits in early 1980's, to 16-bits or 32-bits in mid 1980's, and to 64-bits or more in 1990's. In order to avoid unnecessary delays, technology for parallel communication channels between such CPUs and memory or input/output (I/O) devices must also be rapidly developed. Unfortunately, due to inherent bandwidth limits and electronic interference, large degree parallel electronic communication channels are very difficult to establish, especially where the communication distance is long, for instance longer than a few centimeters. A previously proposed solution was to use fiber-telecommunication teleology where a large amount of parallel information is transmitted in a time-multiplexed serial format. A limitation of this kind of arrangement is that as the bit-rate in each parallel channel increases, electronic hardware for multiplexing and demultiplexing will experience an increasing burden. For example, for a moderately high bit-rate of 500 Mhz/bit-channel, a 32-bit communication will have to use a pair of multiplexer/demultiplexer of 16 GHz, making the hardware very difficult to develop.